Many attempts have been made to pre-treat wood particles such wood wafers of the like for use in the manufacture of a consolidated treated wood product such as particle or wafer board.
For example, it is known to treat wood wafers with ACA or CCA (ammoniacal copper arsenic or chromated copper arsenic). The ACA has been found to be more effective, particularly when added with the wax than CCA. See "Evaluation of the Preservative Effects on Mechanical Properties and Biodurability of Aspen Wafer Board", a paper presented at Pensicola, Fla. on Oct. 5-7, 1982, by E. L. Smithe, H. J. Hall and R. O. Gertjejansen.
U.S. Pat. No. 4,241,113 issued Dec. 23, 1980--Lund also described treated wood wafer for making board where the wood wafers are treated with a preservative compatible with any suitable adhesive such as phenol formaldehyde or the like and states that the binder, wax and other additives may be added separately or in any sequence or in combined form.
It is also known to utilize a boron compound such as borax or boric acid as taught for example in U.S. Pat. No. 4,145,242 issued Mar. 20, 1978 to Chow wherein the boron compound is applied to the wood to preserve the glue bondability of the wood during drying and storage. It was found that the bond could be improved provided the amount of borax on the surface is within a very specific range, however, additions of borax outside the range were detrimental to glueability.
In a recent patent to Knudson and Ehrenfeller, U.S. Pat. No. 4,643,868 issued Feb. 17, 1987, a system is described for applying chemicals to wood particles by first treating the wood particles such as wafers with a wax and then an ammoniacal copper arsenic solution (ACA) and then with adhesive. The concept described is elimination of the necessity for drying prior to consolidation under heat and pressure.
It is also known to use borax as a treating chemical for preserving wood against fungus decay. Products, for example, marketed under the trademark Timbor by U.S. borax (disodium Octiborate Tetrahydrate) rely on diffusion in order to permeate or distribute the borax through the wood. This requires a relatively dilute solution, in other words, a significant amount of moisture be present to attain the required degree of distribution. It is apparent that if this technique is used with wood particles that are subsequently pressed under elevated temperature and pressure conditions, the high moisture content will result in blistering and other defects in the finished product. Furthermore, the borax in solution will contact the resin and result in changing of the resin characteristics and inhibiting of penetration of the resin into the wood.